0011 Matter and it’s Classification:
1. know the difference between pure substances (elements and compounds) and mixtures (solutions, alloys).
Element
Pure
Compound
Matter
Impure
Heterogenous Mixture Homogenous Mixture
Solution Suspension

Figure 8-1
Repeatedly dividing a bar of gold, just like cutting paper repeatedly, produces smaller and smaller groups of atoms, until you come to a single gold atom. Dividing that atom into two parts produces fragments that no longer have the properties of gold.

…distinguish between atoms and elements.
• Atom = the smallest particle of an element that retains the chemical identity of that element.
• An element is a material made from a single type of atom.

Element : a pure substance containing only one kind of atom
• Periodic Table
• Element symbol Latin name
• Sodium
Na
• Potassium
K natrium kalium
• Copper
• Gold
• Lead
Cu
Au
Pb cuprum aurum plumbum

Atoms that compose an element may combine in a variety of ways.
• Gold, Au
• Sulfur, S
8
• Nitrogen, N
2
• Oxygen, O
2

Compounds
–atoms of different elements combined in a fixed ratio
• Compounds have physical and chemical properties different from the properties of their elemental components
• NaCl, sodium chloride or table salt
• Fe
2
O
3
, iron oxide or rust

Mixtures = various combinations of elements, compounds, or both
• Stainless steel is a mixture of the elements iron, chromium, nickel and carbon.
• Our atmosphere is a mixture of nitrogen, oxygen, argon, carbon dioxide, water vapor, and pollutants.

How might we separate the following:
• Iron filings and sand
• Sawdust and rubber washers
• Salt and water
• Oil and water
• Point: Components of any mixture can be separated by physical means.

Classification of Matter
Element
Pure
Compound
Matter
Impure
Heterogenous Mixture Homogenous Mixture
Solution Suspension

– Gold, Au
– Hydrogen, H
2
– Silicon, Si
– Salt, NaCl
– Carbon Dioxide,
CO
2
– Ammonia, NH
3

•
Heterogenous
Mixture
– Sand in water
– Oil and water
– Salt and pepper
•
Homogenous
Mixture
–
Solution
–
Suspension

•
Solution
– Air (N
2
, O
2
)
– Salt water (NaCl,
H
2
O)
– Stainless Steel (Fe,
Cr, Ni, C)
•
Suspension
– Milk (water, solid proteins)
– Blood (water, solid cells, nutrients)
– Fog (air, tiny water droplets)

0011 Matter and it’s Classification:
2. identify component parts of a substance
(atoms, ions, molecules)
• Atom = smallest amount of an element that can exist.
• Ion = at atom that has lost or gained one or more electrons
• Molecule = smallest part of a covalent compound that can take part in a reaction. Ionic compounds do not have single molecules, ‘cause they’re collections of oppositely charged ions.

• describe the physical characteristics of a substance, such as color, hardness, density, texture, and melting point.

• is a change in some property of a substance.
• Usually occur during heating/cooling or when there is a change in pressure.

• characterize the tendency of a substance to transform into a different substance.

• Atoms rearrange during a chemical change, switching partners as previous connections are broken and new ones are formed.
• Evidence?

0011 Matter and it’s Classification:
3. distinguish between physical and chemical properties (e.g. density, melting point, combustibility)
• Physical change
• New attributes result from new set of conditions imposed on the material
• Chemical change
• New attributes are the physical properties of a fundamentally different material

0011 Matter and it’s Classification:
4. identify characteristics of ionic and covalent chemical bonds

Outer electrons = “valence electrons”
Valent = combining power

• Sodium atom
• Loses one electron
• Becomes a sodium ion, Na+
• Stable [Ne]
• Chlorine atom
• Gains one electron
• Becomes a chloride ion, Cl-
• Stable [Ar]

Figure 10-1
Sodium, a highly reactive element, readily transfers its single valence electron to chlorine, which is one electron shy of the “magic” number
18. The result is the ionic compound sodium chloride —ordinary table salt. In these diagrams, electrons are represented as dots in shells around a nucleus.

Courtesy Robert Capece
Figure 10-9
Individual salt crystals reveal a characteristic cube shape.

Figure 10-2
The atomic structure of a sodium chloride crystal consists of a regular pattern of alternating sodium and chloride ions.

Figure 10-5
Two hydrogen atoms become an H
2 molecule by sharing each of their electrons in a covalent bond. This bonding may be represented schematically in a dot diagram ( a ), or by the merging of two atoms with their electron clouds ( b ).

0011 Matter and it’s Classification:
4. identify characteristics of ionic and covalent chemical bonds

• Hydrogen atom
• Has one unpaired valence electron
• Becomes stable by sharing its outer electron with one of carbon’s [He]
• Carbon atom
• Has four unpaired valence electrons
• Becomes stable by sharing its lone electrons with one from hydrogen [Ne]

Figure 10-7
The water molecule and its polarity.

• Ionic
• Electron transfer
• Metal loses e-
• Nonmetals gain e-
• Electrostatic attraction holds the crystal together
• NaCl
• crystal
• Covalent
• Electron sharing
• Two nonmetals share a pair of valence electrons which orbit both atoms, holding them together
• H
2
O
• molecule

Periodic Table Basics:
Element Symbol, Atomic
Number, Average Atomic Mass, Families and Periods.
Figure 8-13
The periodic table of the elements. The weights of the elements increase from left to right. Each vertical column groups elements with similar chemical properties.

0011 Matter and it’s Classification:
5. demonstrate knowledge of the organization of periodic table and its relationship to properties of matter

…compare and contrast families of elements in terms of their chemical properties.
Noble Gases, group VIIIA (18), these elements are stable or nonreactive, ‘cause outer energy level has all the electrons it can hold.

Figure 8-14
A representation of electrons in a number of common atoms.

…compare and contrast families of elements in terms of their chemical properties.
Alkali Metals, group IA (1) are reactive; get stable by giving the one outer electron to a nonmetal atom.
Pure Al in water:
KABOOM!

…compare and contrast families of elements in terms of their chemical properties.
Alkaline Earth Metals, group
IIA (2); reactive, get stable by donating the 2 outer electrons to nonmetal atoms.
Dover chalk cliffs,
CaCO
3

…compare and contrast families of elements in terms of their chemical properties.
Halogens, group VIIA (17); halogens are nonmetals that get stable by gaining one electron (from metal) to fill their outer energy level. For example, Na loses one e- and Cl gains one e- to make
Sodium Chloride, NaCl.

0011 Matter and its classification:
6. identify chemical symbols and interpret formulas

Ionic Compounds:
Metal lose electron(s) and Nonmetal gains electron(s) sodium chloride calcium chloride magnesium oxide aluminum oxide
NaCl CaCl
2
MgO Al
2
O
3

Covalent Compounds:
Two or more Nonmetal atoms share electrons.
water carbon dioxide methane ammonia
H
2
O CO
2
CH
4
NH
3

• --the rearrangement of atoms that occurs when substances undergo chemical change
• During a chemical reaction, a new material is formed by this shuffling of atoms
• Bonds break, new bonds form
• Reactants 
Products

Figure 10-13
In pictorial form, an oxidation reaction involves the transfer of electrons to oxygen atoms. When natural gas (CH
4
) burns, it combines with two oxygen molecules (O
2
) to form a molecule of carbon dioxide (CO
2
) and two molecules of water (H
2
O).


• A chemical equation shows the material about to react to the left of an arrow that points to the newly formed materials.
• 2Na + Cl
2

2NaCl
• 2H
2
O
2

2H
2
O + O
2
• Zn + 2HCl 
ZnCl
2
+ H
2
• CH
4
+ 2O
2

CO
2
+ 2H
2
O